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Giant Palouse earthworms found, but they aren't as 'giant' as expected

April 27, 2010 | 5:54
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SPOKANE, Wash. — Two living specimens of the fabled giant Palouse earthworm have been captured for the first time in two decades in what represents a significant discovery of a creature that has achieved a mythic status in the area.

The giant Palouse earthworm has fascinated scientists for decades after long being written off as an extinct creature. Reports suggested that the worms had a penchant for spitting and smelled like lilies, further enhancing the myth of the earthworm in the agricultural Palouse region on the Washington-Idaho border.

"It's a good day for the worm," said University of Idaho soil scientist Jodi Johnson-Maynard in Moscow, Idaho, who has been leading the search.

The recent discovery of the worms appeared to dispel the myth about the creature's appearance. They don't spit or smell like lilies and they aren't even that giant.

"One of my colleagues suggested we rename it the 'larger-than average Palouse earthworm,'" Johnson-Maynard said when the find was announced Tuesday.

Although they had been thought to grow to 3 feet long, the adult worm measured about 10 or 12 inches fully extended, while the juvenile was 6 or 7 inches.

The worms were translucent, allowing internal organs to appear. They had pink heads and bulbous tails. The adult had a yellowish band behind the head.

The specimens were found March 27 by Shan Xu, an Idaho student, and Karl Umiker, a research support scientist. They also found three earthworm cocoons, two of which have hatched and appear to also be giant Palouse earthworms.

The Palouse earthworm was first reported to the scientific world in an 1897 article in the American Naturalist by Frank Smith. Smith's work was based on four samples sent to him by R.W. Doane of Washington State University in Pullman.

Massive agricultural development soon consumed nearly all of the unique Palouse Prairie -- a seemingly endless ocean of steep, silty dunes -- and appeared to deal a fatal blow to the worm.

In the late 1980s, University of Idaho scientist James Johnson found two worms in a second-growth forest near Moscow. They were the last living specimens found until now.

The worms were considered extinct until 2005, when Idaho graduate student Yaniria Sanchez-de Leon found a specimen near Albion, Wash. But that worm had been cut nearly in half as she was digging a hole.

After that discovery, conservation groups petitioned the U.S. Fish and Wildlife Service to protect the worm as an endangered species, citing as proof the lack of sightings. But the agency said there simply was not enough scientific information to merit a listing.

Most earthworms found in the Northwest originated in Europe, arriving on plants or in soil shipped to the New World. The giant Palouse earthworm is one of the few native species.

"The most important thing about this to me is this is the first time we have an intact, live specimen that we can get DNA from and make a taxonomic description to the species level," Johnson-Maynard said.

Last month's discoveries followed the development of a new high-tech worm shocking probe that was stuck in the ground and used electricity to push worms toward the surface. The probe was deployed starting last summer and proved far less lethal to worms than sticking shovels into the ground to dig them up, Johnson-Maynard said.

The adult was killed so that University of Kansas earthworm expert Sam James could dissect it identify and it as a giant Palouse earthworm. James made that determination on April 16.

The juvenile remains alive at the University of Idaho, where its DNA will be used to identify new specimens.